Field of the Invention
In the past, separate window structures have generally been provided for installation as single hung, hopper and/or glider windows. Wherein a single hung window structure has been utilized for installation as a single hung, hopper and/or glider window, they have generally been relatively complicated and therefore difficult to construct and install, and have often been inefficient in their installation as one or more of these three types of windows.
In particular, such window structures of the past have usually not included a thermal barrier. Wherein thermal barriers have been included in window structures in the past, they have usually either not provided an adequate thermal barrier or have not been sufficiently rigid. In addition, thermal barrier structure of the past has often been complicated and therefore difficult and expensive to manufacture.
Prior window structures, wherein a storm window has been provided in conjunction with a prime window, have usually required separate operation of the prime windows and the storm windows. Wherein simultaneous operation of prime and storm windows have been provided in the past, it has not usually been selective. Further, simultaneous operation of prior prime and storm windows has not generally been possible with simple, easy to construct, inexpensive and efficient structure.
Also, with the window structures of the past, wherein tilt release and upper sash guide structure has been provided, the structure has also often been complicated and inefficient. Further, the tilt release structure of the past has often required manual operation and has not been adapted to automatic operation such as is necessary in conjunction with automatic sash ejector structure.
Balance foot structure of the past has often required special connecting means for a sash balance connected thereto, required complicated structure for holding the balance foot in a predetermined position on relative tilting of the associated sash and frame, has transferred unnecessary torque to the frame during operation of the window sash, and further has twisted unnecessarily with the sash removed from the frame.
Lower sash guide structures in conjunction with balance feet of the past have not usually transferred torque effectively between the balance feet and the window sash and has been inefficient in locking the balance feet in a predetermined position in the window frame on tilting of the sash in the frame.
In prior window structures, the window sash side stiles are often set in grooves in the window frame jambs. Wherein the sash side stiles are not in engagement with the jambs in prior structures, the weather stripping between the sash side stiles and frame jambs has not always been efficient in preventing wind and moisture movement therethrough.
Prior window structures have often included locks for securing window sash in a fixed closed position within a window frame. The lock structure has not, however, always been readily visible, easily operated or particularly efficient in effecting the locking and unlocking function desired.
Structure for securing a window sash in predetermined open or partly open positions has not always been included in prior window structure. Further, wherein such structure has been provided in the past, it has required separate manual operation during opening and/or closing of the window.
Wherein window structures of the past have been provided with a sash which has been movable in the plane of the window frame and tiltable out of the plane of the frame, such structures have generally required separate operation of a tilt release mechanism or the like during pivotal movement of or prior to pivotal movement of the window out of the plane of the window frame. No prior automatic sash ejector structure is known. Accordingly, no structure for preventing operation of automatic sash ejector structure on movement of a sash in a window frame is known.
Prior window screen structure has generally included L-shaped corner brackets for receiving mitered stiles which stiles have in the past been straight between corners. Screen structure of the past has sometimes been held together by screen material secured to the stiles. Separate spring means and/or lift tabs have often been applied in the past to screen structures.